The subject matter disclosed herein relates to a sealing structure between a rotating component and a static component and, more particularly, to a compliant plate seal arrangement manufacturing method.
Dynamic sealing between a rotor (e.g., rotating shaft) and a stator (e.g., static shell or casing) is an important concern in turbomachinery. Several methods of sealing have been used. In particular, sealing based on flexible members has been used that include seal members such as compliant plate seals.
Known brush seals include tightly-packed, generally cylindrical bristles that are arranged in a staggered arrangement to reduce leakage. The bristles have a low radial stiffness that allows them to move in the event of a rotor excursion while maintaining a tight clearance during steady state operations. Brush seals, however, may be generally effective only below a limited pressure differential across the seal. Because of the generally cylindrical geometry of the bristles, the brush seals may have a low stiffness in the axial direction, which limits the maximum operable pressure differential in known brush seals to generally less than 400 psi.
Compliant plate seals have a plate-like geometry that has a significantly higher axial stiffness for a comparable radial stiffness and therefore such seals have the capability of being used with larger pressure differentials than known brush seals. Compliant plate seals, often packed together as a leaf pack, are welded to a housing that supports the compliant seals relative to a rotor (e.g., a rotating shaft). The compliant seals are welded to the housing at an outside diameter of the compliant seals. During the welding process, the compliant seals can shrink which causes distortion and wrinkling of the compliant plates, which can affect the dimensional accuracy and radial stiffness, on the compliant plates, which can lead to several problems including increased axial leakage and rotor heating.